Pyridine → 3-Bromo-4-oxo-6-phenyl-4H-pyran-2-carboxylic acid
Reaction equation
[Br:1][C:2]1[C:7](=[O:8])[CH:6]=[C:5]([C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=2)[O:4][C:3]=1[C:15]([O:17]C)=[O:16].[I-].[Na+].N1C=CC=CC=1>C(C(C)=O)C.O>[Br:1][C:2]1[C:7](=[O:8])[CH:6]=[C:5]([C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=2)[O:4][C:3]=1[C:15]([OH:17])=[O:16]Participants
6
Procedure
Methyl 3-bromo-4-oxo-6-phenyl-4H-pyran-2-carboxylate (587 g) was added to a stirred solution of dry sodium iodide (315 g) in dry methyl ethyl ketone (8 l). The solution was heated under reflux for 5 minutes, then pyridine (152 ml) was added and heating was continued for 31/2 hours. The mixture was cooled, the solid product was dissolved in water (2 l) and the solution was washed with dichloromethane and filtered. The filtrate was diluted to 10 l and acidified with 5 M hydrochloric acid (760 ml) to precipitate the title product (mp 247° C. with decomposition).
Workup
- temperatureThe solution was heated
- temperatureunder reflux for 5 minutes
- temperatureheating
- custom2 hours
- temperatureThe mixture was cooled
- washthe solution was washed with dichloromethane
- filtrationfiltered
- additionThe filtrate was diluted to 10 l
- customto precipitate the title product (mp 247° C. with decomposition)
Sources & evidence
- ORD record
- ord-a3e52bf47c4e422ca34fd90ca43a7076
- Source dataset
- uspto-grants-1981_12
- Patent number
- US04304728
Reaction notes
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